The present invention relates to an electromagnetic relay, and more particularly concerns an assembling structure in which an iron core and a movable iron member are installed.
Conventionally, with respect to electromagnetic relays, for example, Japanese Laid-Open Patent Application No. 2000-222990 has disclosed one of those relays.
In this relay, a gate-shaped fixed iron core around which an exciting coil has been wound is placed in a housing, and a switching mechanism, constituted by a movable contact member and a fixed contact member, is placed in a recessed section of this gate-shaped fixed iron core, and an armature is placed in a manner so as to virtually close the recessed section, and in this arrangement, this armature is made in contact with one of the two leg members of the gate-shaped fixed iron core, while it is made in contact with and separated from the other end of the two leg members, so as to carry out swinging processes; thus, a protrusion formed in the middle of the armature is allowed to push the above-mentioned contact member so as to turn on and off the above-mentioned switching mechanism.
However, the above-mentioned electromagnetic relay has virtually the same shape on the two ends of its armature, and also has virtually the same weight. For this reason, when the swinging process is carried out with one end of the above-mentioned armature being in contact with one of the two leg members of the gate-shaped fixed iron core and the other end being made in contact with and separated from the other of the two leg members thereof, the other end of the armature, which is made in contact with and separated from the iron core, tends to deviate. Consequently, the above-mentioned electromagnetic relay tends to fail to provide stable operation characteristics.
Moreover, the above-mentioned gate-shaped fixed iron core is not assembled onto a spool that has been molded, and consequently, it is necessary to carry out an insert-molding process. Therefore, an expensive insert-molding device, which needs time-consuming and difficult operations in transporting parts, is required, resulting in high production costs.
The present invention has been devised to solve the above-mentioned problems, and its objective is to provide an inexpensive electromagnetic relay in which the adsorb portion of the movable iron member, which is made in contact with and separated from the magnetic pole portion of the iron core, is less susceptible to deviations, and which has stable operation characteristics.
In order to achieve the above-mentioned objective, an electromagnetic relay of the present invention is provided with: an iron core which has a virtually L-letter shape on a plan view with one end serving as a support-receiving portion and the other end serving as a magnetic pole portion, and is provided with an exciting coil wound around in the middle portion thereof; a movable iron member which is supported by a hinge spring adsorb to a corner thereof, and has a virtually L-letter shape on a plan view with one end being supported on the support-receiving portion so as to freely pivot thereon and the other end being allowed to face the magnetic pole portion of the iron core so as to be adsorbed thereon; and a contact unit which allows a fixed contact and a movable contact to contact each other and to separate from each other through rotation of the movable iron member.
In accordance with the present invention, one end of the movable iron member, which is supported by the support-receiving portion of the iron core so as to freely pivot thereon, is designed to have a wider width and to be heavier than that of the other end of the movable iron member that faces the magnetic pole portion of the iron core so as to be adsorbed thereto. Therefore, even when the movable iron member is allowed to pivot through the hinge spring, the other end of the movable iron member is less susceptible to deviation; thus, it becomes possible to provide an electromagnetic relay having stable operation characteristics.
Moreover, since the iron core can be assembled onto a molded spool, it is possible to eliminate the necessity of the insert-molding process, and consequently to provide an inexpensive electromagnetic relay having low production costs.
Another electromagnetic relay of the present invention is provided with: an iron core which has a virtually J-letter shape on a plan view with one end serving as a support-receiving portion and the other end serving as a magnetic pole portion, and is provided with an exciting coil wound around in the middle portion thereof; a movable iron member which is supported by a hinge spring adsorbed to a corner thereof, and has a virtually L-letter shape on a plan view with one end being supported on the support-receiving portion so as to freely pivot thereon and the other end being allowed to face the magnetic pole portion of the iron core so as to be adsorbed thereon; and a contact unit which allows a fixed contact and a movable contact to contact each other and to separate from each other.
In accordance with this invention, in addition to the above-mentioned effects, the length from the corner of the movable iron member to the pivotal tip portion is set to be shorter than an electromagnet block. Consequently, the moment of inertia around the pivotal axis of the above-mentioned movable iron member becomes smaller, thereby making the operation speed of the movable iron member faster; therefore, it is possible to provide an electromagnetic relay having swift operation characteristics.
Moreover, in another embodiment of the present invention, one end of the iron core may be inserted into and attached to a through hole of a spool around which the exciting coil has been wound.
In accordance with the present embodiment, it is possible to eliminate the necessity of an expensive insert-molding device which needs time-consuming and difficult operations in transporting parts, and consequently to provide an inexpensive electromagnetic relay having low production costs.
In still another embodiment of the present invention, the hinge spring may be prepared as a movable contact member.
In accordance with the present embodiment, since a movable contact member is attached to the movable iron member having stable operation characteristics, it is possible to provide an electromagnetic relay having stable switching characteristics and superior response characteristics.
In the another embodiment of the present invention, an insertion-receiving section to which a position regulating protrusion, formed on the bottom face of a base, is fitted so as to freely move therein, is formed in the vicinity of a corner of the movable iron member. Here, the above-mentioned insertion-receiving section in accordance with this aspect may be a recessed section that is formed by an extrusion machining process, or a through hole that is formed by press working.
In accordance with the present embodiment, an insertion-receiving section of the movable iron member is fitted to a position regulating protrusion formed on the bottom face of a base, so as to freely move thereon. For this reason, even when an impact force is externally applied thereto, the movable iron member is position-regulated by the above-mentioned protrusion so that it is possible to prevent the hinge spring attached to the movable iron member from being plastically deformed, and consequently to prevent the movable iron member from coming off.